Use routing policies

Routing policies in webMethods API Gateway determine the direction of incoming requests to different backend resources or endpoints based on specified conditions. Use these policies to control the flow of traffic within webMethods API Gateway to implement various routing strategies, such as load balancing, versioning, A/B testing, and canary deployments.

1. Open the menu options and select APIs.
2. Click Create API.
3. Select Import API from URL.
4. Provide the following information.
   • URL- http://petstore.swagger.io/v2/swagger.json
   • Name- Petstore
   • Description- The Petstore API is a RESTful web service that allows users to interact with a virtual pet store.
   • Version- 1.0
5. Click Create.
   The Petstore API is created, and the Straight Through Routing policy is applied by default. The Petstore API’s details page appears.
6. Click Activate to activate the API.
7. To check the Straight Through Routing policy that is applied by default, click Policies > Routing.

   In this example, the default application of Straight Through Routing policy simplifies the API configuration process.

   Once the Petstore API is configured and exposed, clients can interact with the API endpoints to perform various actions. The actions include retrieving a list of available pets, adding new pets to the store, updating pet details, placing orders, and more. webMethods API Gateway directly routes each API request that is made by the client to the backend service.

   The following table lists the routing policies that webMethods API Gateway offers and outlines the specific use cases for each policy:

   Use case	Routing policy
   Objective. Expose existing backend services through an API with minimal added complexity. Scenario. Optimize traffic flow between network segments or zones without intermediate processing. Example. In fast networks like data centers, straight-through routing minimizes latency and overhead. This approach ideally suits applications that require low latency and high throughput, such as real-time video streaming, online gaming, or financial trading.	Use the Straight Through Routing policy to ensure minimal latency and overhead.
   Objective. Direct incoming requests to different backend resources based on specified conditions or criteria. Scenario. Handling sensor data from various devices differently based on specific conditions. Example. In a smart agriculture system, sensors monitor soil moisture levels across different fields. Conditional routing directs data from sensors that detect low moisture levels to irrigation systems for immediate action.	Use the Conditional Routing policy to handle data differently depending on predefined conditions.
   Objective. Effectively distribute incoming network traffic evenly across multiple servers or resources to optimize usage of resources and improve system performance. Scenario. Handling high volumes of incoming requests in a web-hosting environment. Example. During peak shopping seasons, an e-commerce platform uses load balancer routing to evenly distribute traffic across servers, preventing overload and enhancing performance for a seamless user experience.	Use the Load Balancer Routing policy to evenly distribute incoming requests across servers.
   Objective. Make sure that you secure communication between API Gateway and backend systems by including authentication credentials within transport headers. Scenario. Integration with legacy systems or third-party APIs requiring transport-level authentication. Example- An enterprise application interacts with a legacy backend that is protected by Basic Authentication over HTTPS. Configuring the Outbound Auth - Transport policy with the appropriate credentials enables webMethods API Gateway to seamlessly authenticate and authorize outgoing requests to the legacy system.	Use the Outbound Auth – Transport policy to authenticate outgoing requests.
   Objective. Embed authentication credentials within the payload message of outgoing requests to satisfy requirements of the native API. Scenario. In instances where APIs mandate authentication credentials within the message payload. Example. An application needs to interact with a third-party service secured with SAML-based authentication. By configuring the Outbound Auth - Message policy with the necessary SAML credentials, webMethods API Gateway seamlessly embeds these credentials within the outgoing request’s payload, making sure you secure communication without added complexity.	Use the Outbound Auth – Message policy to embed authentication credentials within the message payload for secure communication with APIs.
   Objective. Facilitate seamless communication between a legacy system by using a JMS queue and a modern RESTful API. Scenario. Modernizing a service by offering a RESTful API for order placement while you maintain compatibility with legacy JMS-based communication. Example. A legacy system communicates through a JMS queue for order processing. The company aims to modernize its service by providing a RESTful API for order placement. JMS/AMQP routing policy acts as a bridge between the legacy system and the RESTful API, ensuring smooth transition and compatibility.	Use the JMS/AMQP Routing policy to seamlessly route requests between the two environments.